Technical Field
The present disclosure relates to a digital holographic microscope.
Description of Related Art
A digital holographic microscope can obtain the outward appearance of a sample by recording the interference pattern of two light beams. In greater detail, an object light beam impinging on the sample is reflected to an image sensing device to form an interference pattern with a reference light beam. The interference pattern is recorded by the image sensing device and is transformed into a digital signal. The outer appearance of the sample can be determined from the digital signal and an image of the sample is generated from such a determination.
Reference is made to FIG. 1 which is a schematic diagram of a conventional digital holographic microscope. The digital holographic microscope includes a light source 910, a dichroic mirror 920, an image sensing device 930, a supporting substrate 940, and a reflective mirror 950. The supporting substrate 940 is configured for supporting a sample 300. A light beam 912 emitted from the light source 910 can be split into a reference light beam 914 and an object light beam 916 after passing through the dichroic mirror 920. The object light beam 916 passes through the supporting substrate 940, impinges on the sample 300, and is then reflected to the image sensing device 930. Moreover, the reference light beam 914 impinges on the reflective mirror 950, is reflected to the dichroic mirror 920, and is reflected to the image sensing device 930 by the dichroic mirror 920. However, in this digital holographic microscope, the dichroic mirror 920 needs to be aslant disposed between the sample 300 and the image sensing device 930. An angle, such as 45 degrees, is formed between the dichroic mirror 920 and the light collecting surface 932 of the image sensing device 930, resulting in a distance h between the sample 300 and the image sensing device 930. Therefore, the size of the digital holographic microscope remains large and cannot be reduced.